Printed circuit boards which comprise a conductive metal coating or foil on one or both sides of a non-conductive material such as a resin (reinforced or otherwise) are utilized in the electrical and electronic industries to a great extent. The metal coating which may be relatively thin in nature is etched in a predetermined pattern so as to provide a flow of electricity between two or more points. With the advent of more sophisticated equipment, printed circuit boards have become increasingly important in the industry. The printed circuit boards which are now in use comprise a wide variety of systems. When using certain resins as the basis for the laminate materials on which the conductive metal is mounted, certain disadvantages crop up from time to time. This is particularly true when conventional means of etching, soldering, drilling, etc. are employed to prepare the desired board. For example, surface mounting components on printed circuits which are prepared by means of vapor phase soldering and thermo-compression bonding place severe thermal stresses on the conductive metal-to-resin bonds of commonly used epoxide resin-base laminate materials. In order to overcome this disadvantage, manufacturers of circuit boards have utilized various resin systems which possess higher glass transition temperatures and higher bond strengths at soldering temperatures, examples of said resin systems including triazine resins, polyimide resins, etc. While overcoming the aforementioned disadvantage of the thermal stress, the solution to one problem has resulted in another disadvantage, namely, that the resin systems so employed are substantially more expensive than the epoxide resins. In addition to the more expensive price, these higher temperature resin systems also exhibit increased chemical resistance as compared to the epoxy resins. A negative point or disadvantage to this increasing chemical resistance relates to more difficult smear removal or etchback of drilled interconnecting holes prior to plating through these holes to form a desired circuit.
As will hereinafter be set forth in greater detail, it has now been discovered that a more inexpensive laminate may be prepared which will not possess the disadvantages hereinbefore set forth in that it may be prepared in a more economical manner while retaining the desirable characteristics necessary for use in electrical and electronic equipment.